Laboratory Quality Control.
Quality control is not a final inspection. It is a series of checks placed at the points where an error, if it passes, gets built into everything that follows.
The principle: catch error before it compounds
Fabrication is sequential. A die that is fractionally wrong produces a coping that is wrong, which is then veneered, finished and glazed — with several hours of work invested in a restoration that was never going to fit.
Effective quality control is therefore front-loaded. The checks that matter most happen early, before value has been added, because that is where correction is cheap. An inspection performed only at dispatch catches problems at the most expensive possible moment.
Records and model verification
The first check is of what arrived. Is the margin identifiable around its full circumference? Does the bite record seat on the casts without rocking? Is the opposing arch complete? Do the models articulate in a way consistent with the bite record?
This is the stage at which most calls to the practice originate, and deliberately so. Almost every problem that can be traced back to the records is cheaper to resolve here than at any later point.
For digital cases the equivalent check is of the file: margin visibility, holes in the data, insertion axis, and whether the bite alignment produces occlusal contacts consistent with the case.
Substructure and framework
Before any aesthetic work begins, the coping or framework is assessed for fit on the die and for whether it will actually support the ceramic that goes on top of it. A framework that fits but does not follow the reduced anatomy leaves veneering ceramic unsupported at the cusp tips, which is where chipping starts.
At Fairmont this is one of the two points at which cases are inspected under the microscope — once after the wax-up is complete and again after the frame is finished — so that the degree of fit is verified before any aesthetic work is committed to.
Connector dimension is assessed at this stage in multi-unit work. Connectors that are undersized or badly positioned occlusogingivally are a structural problem that cannot be corrected once the case is veneered.
Contacts, contour and occlusion
Proximal contacts are checked for position and tightness against the adjacent teeth as recorded. Emergence and contour are assessed against what the tissue will tolerate, not simply against an ideal form. Occlusion is verified against the mounted casts in intercuspation and in excursion.
This is where an inaccurate record shows itself most visibly, because a restoration built correctly against a wrong bite will be wrong in the mouth in a way that adjustment cannot fully recover.
Surface and finish
Surface texture and polish are functional matters as much as aesthetic ones. A rough ceramic surface abrades the opposing dentition considerably faster than a properly polished one, and this is the reason chairside adjustment without repolishing is such a persistent problem — the restoration leaves the laboratory polished and arrives in function rough.
If you adjust a ceramic restoration at the seat appointment, repolish it properly with a ceramic polishing sequence. Glaze alone does not survive grinding, and the patient's opposing enamel pays for the omission over years.
Documentation and dispatch
Traceability matters for materials in particular. Alloy identification certificates are provided for your records, and every appliance and product is disinfected before it leaves the laboratory.
Dispatch checks confirm that what is in the box matches the prescription, that any returned records are included, and that anything the practice needs to know at seating travels with the case.
What a remake pattern tells you
Individual remakes are noise. Patterns are information, and they are worth tracking because the pattern usually identifies the cause more reliably than any single case does.
Remakes clustering on fit point back to records — impressions, scans or preparation geometry. Remakes clustering on shade point to shade-taking conditions rather than to ceramic work. Remakes on occlusion point to bite registration. Remakes concentrated on one restoration type or one tooth position often point to a clearance issue specific to how those teeth are being prepared.
A laboratory that records why cases come back, and a practice willing to discuss what it is seeing, can usually identify a systematic cause within a handful of cases. Without that exchange, both sides absorb the same failure repeatedly and attribute it to bad luck.
The practice is part of the quality system
Roughly speaking, the laboratory controls fabrication and the practice controls the inputs and the delivery. Neither can compensate fully for the other, and the restorations that fail are usually the ones where a weakness at one end met a weakness at the other.
The practice-side contributions that matter most are consistent tissue management, verified clearance, an accurate bite record, a prescription that states intent and constraints, and proper repolishing after any chairside adjustment. None of these are onerous, and each removes a whole class of problem.
The delivery appointment itself is part of the system too. Checking the fit on the die before trying it in, verifying contacts before checking occlusion, and adjusting in the correct order all reduce the chance of a case being condemned for a problem that was actually sequencing.
What quality control cannot recover
It cannot recover information that was never captured. A margin obscured at the moment of impression or scan is not retrievable by any laboratory process, and neither is an occlusal relationship recorded with the patient not in maximum intercuspation.
This is the honest limit of the discipline, and it is why the checks on arriving records exist. Quality control at the bench protects the case from errors introduced at the bench. Errors introduced at the chair can only be identified and referred back — which is exactly what the early-stage checks are designed to do.
In short
- Front-load the checks — correction is cheapest before value is added
- Verification of arriving records is where most laboratory calls originate
- Fairmont inspects under the microscope after wax-up and after frame finish
- Repolish properly after any chairside ceramic adjustment; glaze does not survive grinding
- No laboratory process recovers detail that was never captured
More on laboratory communication
Discuss a case
Where a case sits between options, a short conversation before preparation is usually quicker than resolving it afterwards.